This proposal seeks support for the UMass Worcester Prevention Research Center (UMW-PRC), initially funded by the CDC in 2009 as a developmental PRC. Funding will support the growth and enhancement of a comprehensive core infrastructure that fosters applied public health research partnerships with state and local departments of public health and numerous community partners. Our faculty conduct intervention research, implementation research and public health practice-based research that targets the CDC Winnable Battles of nutrition, physical activity and obesity in the Worcester, MA area. The UMW-PRC has six priority areas: racial and ethnic health disparities, the built environment and systems, comorbid obesity and mental health, child and adolescent health, worksite health promotion, and community-clinical linkages. In the proposed funding cycle, the UMW-PRC will further its role as 1) an institutional leader in applied public health research, 2) an integral part of the collaborative public health system within Worcester, MA, 3) a statewide resource for applied public health research expertise, and 4) a national model for bidirectional applied public health research that integrates academic medicine, public health, health care and communities. This will be accomplished through innovations in each of the PRC programmatic components: administration and infrastructure, community engagement and technical assistance, communication and dissemination, training, and evaluation. Building from this infrastructure, our proposed applied public health prevention research project will be implemented in the racial/ethnically diverse Union Hill neighborhood, which the City of Worcester has prioritized for revitalization due to its high rates of crime, poverty and unemployment, deteriorating built environment, and high chronic disease burden. Targeted resource investments aim to improve crime and safety and economic development. Simultaneously, Union Hill will be targeted by a Massachusetts Department of Public Health (MDPH) Mass in Motion/Community Transformation Grant (MiM- CTG) to implement public policy and environmental improvements to promote physical activity and healthy eating and reduce obesity. Perceived social norms, limited parental efficacy to influence child obesogenic behaviors and limited parenting skills related to child obesogenic behaviors may reduce the impact of built environment interventions. The proposed study will test the impact of the built environment intervention plus a family-focused community health worker (CHW)-delivered component to improve ability of families to navigate their environment and promote healthy eating and activity through improvements in social norms, parental efficacy, and parenting skills, compared to the built environment intervention plus an attention control CHW- delivered component. The study uses a quasi-experimental design to assess impact on child and parent diet, physical activity and BMI. We will use MDPH statewide child BMI data to compare impact of the combined built environment interventions in Union Hill to the MiM-CTG program only in comparable MA urban communities.